Black tank leaking at tank outlet

[Yoda]

Mine are sealed with byutal mastic and the clamp. However nothing you do will solve this unless you block your tank from movement. I have found on my unit the tanks are restrained from movement by the fittings only. I suggest getting rigid foam and block the tank from for/aft movement before reconnecting. Also check for vertical movement and block accordingly. You will be amazed how much movement is allowed. Once done the fittings should hold no matter what method you chose for attachment.

Keith

[Cate&Rob]

abeebe69

Hi Alan, thanks for the update.

I think you are on the right track with trying to block the tank and outlet pipe into position for proper alignment of the valve flange into the tank opening. Any side load or lack of perfect alignment of these two parts is going to be a problem for a caulked and clamped connection. Were you able to find an O ring that fit ?

I would be inclined to fit the flange to the tank and then work on moving/blocking the tank as Yoda Keith suggests to align with the gate valve and outlet piping. You can also cut the ABS drain “manifold” into sections to make it easier to work with. I cut mine into 3 pieces, one for each gate valve. The ABS is then connected back together with rubber flex couplings available from Home Depot or similar.

I agree that production assembly seems to count on the plumbing connections to hold the tank in position. Remember that there are the drain pipe from the toilet and the vent stack connections “fighting you” as you try to shift the black tank position. This is why I went with making the drain manifold more “flexible”.

Rob

[abeebe69]

Mine are sealed with byutal mastic and the clamp. However nothing you do will solve this unless you block your tank from movement. I have found on my unit the tanks are restrained from movement by the fittings only. I suggest getting rigid foam and block the tank from for/aft movement before reconnecting. Also check for vertical movement and block accordingly. You will be amazed how much movement is allowed. Once done the fittings should hold no matter what method you chose for attachment.

Keith

Hi Keith, I had not checked for movement of the tank itself, did not even think of that. Once I empty the tank, I will see how much play there is. Hoping there isn't a lot since that would cause issues with the toilet and the vent tube as well, but better to be on the safe side.

Alan

[abeebe69]

abeebe69

Hi Alan, thanks for the update.

I think you are on the right track with trying to block the tank and outlet pipe into position for proper alignment of the valve flange into the tank opening. Any side load or lack of perfect alignment of these two parts is going to be a problem for a caulked and clamped connection. Were you able to find an O ring that fit ?

I would be inclined to fit the flange to the tank and then work on moving/blocking the tank as Yoda Keith suggests to align with the gate valve and outlet piping. You can also cut the ABS drain “manifold” into sections to make it easier to work with. I cut mine into 3 pieces, one for each gate valve. The ABS is then connected back together with rubber flex couplings available from Home Depot or similar.

I agree that production assembly seems to count on the plumbing connections to hold the tank in position. Remember that there are the drain pipe from the toilet and the vent stack connections “fighting you” as you try to shift the black tank position. This is why I went with making the drain manifold more “flexible”.

Rob

The o-ring was on the flange that went into the tank, so I did not have to find one. What is crazy is that with the tank half full of water, it is not leaking, and I have not even put the clamp on yet. Going to let it sit for a few more days and then add some additional water sealing tape and then a couple of clamps to hold the whole thing together. Hoping for the best and a long-term fix.

Alan

[Yoda]

Hi Keith, I had not checked for movement of the tank itself, did not even think of that. Once I empty the tank, I will see how much play there is. Hoping there isn't a lot since that would cause issues with the toilet and the vent tube as well, but better to be on the safe side.

Alan

Alan - it does not take much to work a connection apart over time. I guess mine are about 1/2" for aft, but some areas can move vertical more than others (probably the toilet and sink connections). Ill know more when I get to blocking it and adding the strapping to my rear one.. Now the water tank is a different matter.

Keith

[abeebe69]

So, after letting it sit for a few days, it started leaking again. I ended up draining the tank and taking the entire assembly apart again. After letting it dry out and cleaning it up, I decided to try something I remember from my military days in maintenance. We used to have these drop tanks on the airplane, and there was an o-ring that would be on the pipe for sealing it to the airplane. We would use petroleum jelly to help seal these so they would not leak, plus it allowed the o-ring to slide in without binding. I didn't have any on hand, but I did have some anti-seize grease. I read the instructions and it said it was good for packing (another term for sealing o-rings). Once I greased it up real good, I then slid it back into the outlet of the tank. This time, I noticed it actually popped into place. This is because there is a lip inside the outlet of the tank that the o-ring should go past. I then put the clamp back on and re-assembled everything. I am now on day two of watching it after I filled the tank up with 10 minutes of water. So far, so good.

Going to give this another day or so to see how it holds up. Still not liking how this is set up, and how rigid it is, but if it starts to leak again, then it will be time to cut out all the piping and re-do it with flexible connectors so that it can sit properly.

Fingers crossed.

Alan

[Jlawles2]

One of the things I keep in my arsenal of strange stuff you may need when doing jobs is PLUMBERS GREASE. https://www.homedepot.com/p/Oatey-1-...0620/203489444 Designed to lubricate o-rings and packings in valves. It's almost like an NLGI#2 grease in thickness. I have used it on several o-rings to assist with installation.

Another one to consider (not in my inventory yet, but next time I think about it when in the store ) https://www.homedepot.com/p/DANCO-1-...0360/203193502

[abeebe69]

One of the things I keep in my arsenal of strange stuff you may need when doing jobs is PLUMBERS GREASE. https://www.homedepot.com/p/Oatey-1-...0620/203489444 Designed to lubricate o-rings and packings in valves. It's almost like an NLGI#2 grease in thickness. I have used it on several o-rings to assist with installation.

Another one to consider (not in my inventory yet, but next time I think about it when in the store ) https://www.homedepot.com/p/DANCO-1-...0360/203193502

Joseph, great ideas. Need to get some for my toolkit as well.

Thanks

Alan